Motor vehicles use a stabilizer bar installed across the frame of the vehicle between the lower control arms of the vehicle's suspension system to control vehicle sway during turns. When a vehicle travels around a curve, the centrifugal force tends to keep the vehicle body moving in a straight line, causing the vehicle to lean outward, i.e., away from the direction of the turn, putting additional compressive force on the outer coil spring and causing the outer control arm to move upward, which carries one end of the stabilizer bar upward. The inner coil spring is placed in tension during the turn as there is less weight on the inner control arm, which lowers the control arm and carries the opposite end of the stabilizer bar downward. Thus, when turning a vehicle, the outer end of the stabilizer bar is carried upward and the inner end is carried downward, causing a rotational or twisting movement of the stabilizer bar. Therefore, the stabilizer bar must be mounted to the frame using a mounting system which allows the stabilizer bar to rotate.
Prior art systems mount the stabilizer bar on the vehicle frame with a U-shaped bracket securing a rubber or rubber like support having a bore equal in size to the outer diameter of the stabilizer bar. Typically, the stabilizer bar is made of steel bar stock having a generally smooth exterior.
When the stabilizer bar rotates within the rubber support member, i.e., during a turn, a squeak or other audible noise is produced as a result of the friction occurring between the stabilizer bar and the rubber support. It is believed that the stabilizer bar bushing squeaks due to the high frictional coefficient of rubber, especially at low temperatures (below 0 degrees C.). While this noise does not affect the performance of the vehicle, it is irritating to the vehicle owner and results in consumer complaints and increased warranty costs.
Moreover, because the rubber bushing is providing access of the bar through a very narrow slit installation is more difficult than the "snap on" feature of the present invention.
For a detailed discussion of the operation of a stabilizer bar and stabilizer bar bushing reference is made to U.S. Pat. No. 5,118,070, incorporated herein by reference.
In view of the foregoing, there is a need for a stabilizer bar bushing which has a low friction, highly abrasion resistant material adhered thereto to reduce and/or eliminate the problem of unwanted noise and facilitate insertion of the stabilizer bar within the bushing.
It is an object of the present invention to provide a stabilizer bar bushing which has a low friction, highly abrasion resistant material adhered thereto to reduce and/or eliminate the problem of unwanted noise and facilitate insertion of the stabilizer bar within the bushing. Another object of the present invention is to provide a process such that the rubber does not bleed and contact the stabilizer bar. Yet another object of the invention is to provide a stabilizer bar bushing and method of manufacture that is simple and economical.